silylenes 1a–c are obtained from the reductive debromination of the corresponding dibromosilanes in the presence of DMAP. Their distinctly different thermalisomerization reactions via C–H bond activation, dearomative ring expansion and silyl migration are discussed. Furthermore, complexes 1 dissociate at elevated temperatures, providing the corresponding free silylenes in situ, which are even capable
DMAP 稳定的甲硅烷基 1a-c是在 DMAP 存在下通过相应二溴硅烷的还原脱溴获得的。讨论了它们通过C-H 键活化、脱芳环扩展和甲硅烷基迁移的明显不同的热异构化反应。此外,配合物1在高温下解离,原位提供相应的游离甲硅烷基,其甚至能够单点活化 H 2。此外,钾取代的以硅为中心的自由基2与( t Bu 3 Si) 2 SiBr 2的过度还原分离。
Isolation of a Relatively Air‐Stable, Bulky Silyl‐Substituted, Neutral Silicon‐Centered Radical
radical 1 was synthesized and fully characterized by single‐crystal X‐ray crystallography, cyclic voltammetry (CV), and EPR spectroscopy. With its extremely sterically encumbered radical center, 1 is stable in the solid state in air for 16 hours without showing signs of decomposition. Thus 1 is the most robust trisilyl‐substituted silyl radical to date and a promising candidate for application as electrode
合成了庞大的超甲硅烷基取代的(t Bu 3 Si)硅中心基1,并通过单晶X射线晶体学,循环伏安法(CV)和EPR光谱进行了全面表征。1具有极高的空间位阻自由基中心,在空气中固态1可以稳定16小时,而没有分解迹象。因此,1是迄今为止最坚固的三甲硅烷基取代的甲硅烷基,并且有望用作有机自由基电池的电极材料。此外,发现它是一种强力的脱卤试剂,因此可能在有机合成中得到应用。
Synthesis, Characterization, and Crystal Structure of Cyclotrisilene: A Three-Membered Ring Compound with a Si−Si Double Bond
obtained by the reaction of the dibromotrisilane 1 and the tribromodisilane 2 with sodium in toluene [Eq. (1)]. The X-ray crystal structure of 3 shows that the three-memberedring is almost an isosceles triangle and has a twisted Si-Si double bond with a length of 2.138(2) Å.
one-electron oxidation with 1.0 equiv of Ph(3)C(+)·Ar(4)B(-) (Ar(4)B(-) = tetrakis[4-(tert-butyldimethylsilyl)-2,3,5,6-tetrafluorophenyl]borate) in benzene to afford the NHC-stabilized silylene radicalcation [((t)Bu(3)Si)(2)Si←NHC(Me)](•+)·Ar(4)B(-) (3). The radicalcation 3 was isolated as air- and moisture-sensitive yellow crystals and structurally characterized by X-ray crystallography and electron
Heavy cyclopropene analogues R4SiGe2 and R4Ge3 (R = SiMe Bu2) – New members of the cyclic digermenes family
作者:Vladimir Ya. Lee、Hiroyuki Yasuda、Masaaki Ichinohe、Akira Sekiguchi
DOI:10.1016/j.jorganchem.2006.03.049
日期:2007.1
1H-Siladigermirene R4SiGe2 (2a) and 1H-trigermirene R4Ge3 (2b) (R = SiMe'Bu,) with a Ge=Ge double bond were synthesized by the reaction of tetrachlorodigermane RGeCl2-GeCl2R with dilithiosilane R2SiLi2 and dilithiogermane R2GeLi2, respectively. The skeletal Ge=Ge double bond of 2a is trans-bent (51.0(2)degrees) with a bond distance of 2.2429(6) angstrom. The reaction of both 2a and 2b with CH2Cl2 resulted in the formation of unusual four-membered ring compounds 5a and 5b as a result of a ring expansion reaction. 1H-Trisilirene 7a and 3H-disilagermirene 7b with an Si=Si double bond also smoothly reacted with CH2Cl2 to yield the four-membered ring systems 8a and 8b, respectively. (c) 2006 Elsevier B.V. All rights reserved.